Effects of V_2O_5 doping on the structure and properties lead-free KNN-LS-BF piezoelectric ceramics

摘要

Lead-free [0.996(0.95Na_(0.5)K_(0.5)NbO_3-0.05LiS-bO_3)-0.004BiFeO_3]-;cmol %V_2O_S (KNN-LS-BF-xV_2O_5) piezoelectric ceramics have been fabricated by the solid-state reaction process and the effects of V_2O_5 doping on the structure and properties of the ceramics have been studied. The results reveal that the addition of V_2O_5 significantly improves the sinterability of KNN-LS-BF ceramics and the comprehensive properties. X-Ray diffraction (XRD) data shows that a small amount of V_2O_5 do not change the phase structure of KNN-LS-BF with smaller and more uniform grains. Main property parameters of KNN-LS-BF-xV_2O_5 ceramics sintered at a low temperature of 1,060 ℃ are optimized around x = 0.3 mol % with a high piezoelectric coefficient d_(33) of 183pC/N, a planar electromechanical coefficient k_p of 0.25, a high dielectric constant ε_r of 638.83 and a low dielectric loss tanδ of 0.7 % at 1 kHz, as well as a high mechanical quality factor Q_m of 53.87.